<select name="{$name}" class="form-control" {$required?'required':''} {$htmlAttr}>
    {notempty name="hasEmpty"}
    <option value="">--请选择--</option>
    {/notempty}
    {volist name="options" id="vo"}
        <option value="{$key}" {$value==$key&&$value!==''?'selected="selected"':''}>{$vo|strip_tags|trim}</option>
    {/volist}
</select>